GB2560935A

GB2560935A - Load handling machine

Info

Publication number: GB2560935A
Application number: GB1704977.6A
Authority: GB
Inventors: John Clarke Kevin
Original assignee: JC Bamford Excavators Ltd
Current assignee: JC Bamford Excavators Ltd
Priority date: 2017-03-28
Filing date: 2017-03-28
Publication date: 2018-10-03
Also published as: GB201704977D0

Abstract

A method of operating a load handling machine 10, the machine having a first part 16 rotatably mounted relative to a second part 12. The first part consists of a load handling arm, 20, 32, and 34. The system further comprises an actuator for rotating the first part relative to the second part 46, a sensor system for determining the rotational position of the first part relative to the second part 44 and first and second operator input devices 26. The first operator input device is used to provide an input speed of rotation of the first part relative to the second part, the second operator input device is used to indicate a need to align the first part relative to the second part at an alignment position. A control system (48, fig 2) operates to slow the rotation of the first part as the alignment position is approached and stop the first part at the alignment position, overriding the input of the first operator input device if necessary.

Description

(54) Title of the Invention: Load handling machine

Abstract Title: Method for aligning the boom arm on a load handling machine (57) A method of operating a load handling machine 10, the machine having a first part 16 rotatably mounted relative to a second part 12. The first part consists of a load handling arm, 20, 32, and 34. The system further comprises an actuator for rotating the first part relative to the second part 46, a sensor system for determining the rotational position of the first part relative to the second part 44 and first and second operator input devices 26. The first operator input device is used to provide an input speed of rotation of the first part relative to the second part, the second operator input device is used to indicate a need to align the first part relative to the second part at an alignment position. A control system (48, fig 2) operates to slow the rotation of the first part as the alignment position is approached and stop the first part at the alignment position, overriding the input of the first operator input device if necessary.

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Load Handling Machine

The present invention relates to a load handling machine.

Certain load handling machines have one part of a machine which is capable of slewing relative to another part of the machine. It is sometimes desirable to quickly align the two parts of the machine.

Thus, according to the present invention there is provided a method of operating a load handling machine, the machine having a first part rotatably mounted about a substantially vertical axis relative to a second part, the first part defining a load handling arm, an actuator for rotating the first part relative to the second part, a sensor system for determining the rotational position of the first part relative to the second part, a first operator input device operable by a variable amount for indicating a user input speed of rotation of the first part relative to the second part, a second operator input device for indicating a need to align the first part relative to the second part at an alignment position, and a control system for receiving signals from the sensor system, the first operator input device and the second operator input device, the control system being operable to slow and stop the actuator, the method including the steps of

a) starting with the first part not at the alignment position, and the first operator input device operated to indicate a user input speed of rotation, and the second operator input device operated to indicate a need to align the first part with the second part and with the first part moving towards the alignment position,

b) as the first part approaches the alignment position the control system controls the actuator according to a protocol to slow an actual speed of rotation of the first part below the user input speed of rotation,

c) then, when the first part reaches the alignment position the control system stops the actuator.

The present invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIGURE 1 is a schematic side view of a load handling machine according to the present invention

FIGURE 2 is a schematic view of certain features of the load handling machine of figure 1,

FIGURE 3 shows a protocol for slowing and stopping slewing of a structure of the machine of figure 1, and

FIGURE 4 shows an alternative protocol for slowing and stopping the upper structure of the machine of figure 1.

With reference to figure 1 there is shown a load handling machine in the form of a rotating telehandler 10. The rotating telehandler has a lower structure in the form a chassis 12 which includes ground engaging means in the form of a pair of wheels 14 and a pair of wheels 15. Upper structure 16 is rotatable (or slew able) about a substantially vertical axis A relative to the chassis 12. The upper structure 16 includes an operator cab 18 and a boom, in this case a telescopic boom 20. The cab includes a seat 22 and various operator controls including a first operator input device, in this case in the form of a joystick 24 and a second operator input device 26.

The boom is pivotally mounted to the upper structure 16 at boom pivot 28. An actuator in the form of hydraulic ram 30 is connected at one end 30A to the upper structure at a location P remote from pivot 28 and at an opposite end 30B to the boom at a location B remote from pivot 28.

The boom includes a first part 32 and a second part 34 which is telescopically slideable within the first part 32. An actuator (not shown) is operable to extend the boom by moving the second part 34 in the direction of arrow C relative to the first part 32, and is also operable to retract the boom by retracting the second part 34 in the direction of arrow D relative to the first part 32. A material handling implement 36 is mounted on end 34A of the second part 34 at pivot 38. An actuator in the form of a hydraulic ram 40 is connected at a first end 40A to the material handling implement at a location E remote from pivot 38, and at a second end 40B to the second part 34 at a location F remote from pivot 38.

The rotating telehandler 10 further includes a boom extension sensor 42 which provides a signal indicative of an amount of boom extension. The rotating telehandler also includes a rotational positional sensor 44 which is capable of providing a signal indicative of the rotational position of the upper structure 16 relative to the chassis 12. The rotated telehandler also includes a boom lift angle sensor 43 which is capable of providing a signal indicative of the lift angle of the boom.

An actuator, in the form of a slew motor 46 is capable of selectably rotating the upper structure 16 relative to the lower structure 12.

The slew motor 46 is controlled by a control system 48.

The control system includes a processor 52. The processor may be a microprocessor. Alternatively the processor may be two or more processors working in conjunction with each other. The control system also includes memory 54 which is accessible by the processor 52. The memory includes predetermined values defining a protocol (see figure 3). The predetermined values may be stored in the form of a database, and/or in the form of a look-up table, and/or in the form of a mathematical function and/or in the form of a map. The memory may be stored on the machine, or alternatively the memory may be stored remotely and accessible by the processor via wired or wireless connections.

The seat 22 and first and second operator input devices, together with other controls (not shown) are arranged within the cab 18 such that the cab has a front 18A and a back 18B.

The chassis has a first end 12A and a second end 12B.

Operation of the rotating telehandler is as follows:4

Control means (not shown) allow the operator to drive the machine over the ground either in the direction of G or H. Further control means (not shown) allow the machine to be steered when moving the direction of G or H.

The joystick 24 allows the upper structure 16 (and hence the cab 18) to be slewed relative to the chassis 12 either clockwise when viewed in the direction of arrow J or anticlockwise. In one example, moving the joystick to the right causes the upper structure to slew in a clockwise direction when viewed from the direction of arrow J and moving the joystick to the left causes the upper structure to slew anticlockwise when viewed in the direction of arrow J. The joystick can be moved by a variable amount for indicating a user input speed of rotation of the upper structure relative to the chassis e.g. a desired speed of rotation of the upper structure relative to the chassis. Thus, moving the joystick to its maximum right position indicates a desire to rotate the upper structure at a maximum speed in a clockwise direction. However, moving the joystick only partially to the right (i.e. not to the rightmost position but between the rightmost position and the neutral position of the joystick) indicates desire to rotate the upper structure at a speed less than the maximum speed in a clockwise direction. The same applies in mutatis mutandis when the joystick is moved to the left.

The joystick 24 also allows the operator to extend the boom in the direction of arrow C or retract the boom in the direction of arrow D.

A second joystick (not shown) also allows the operator to extend or retract hydraulic ram 30, which in turn raises the boom in the direction of arrow K (thereby increasing the boom angle) or lowers the boom in the direction of arrow L (thereby decreasing the boom angle). In one example, moving the second joystick forwards relative to the operator causes the hydraulic ram 30 to retract whereas moving the second joystick backwards relative to the operator causes the hydraulic ram 30 to extend. The second joystick can be moved by a variable amount forwards indicating a user input speed of lowering of the boom e.g. a desired speed of lowering of the boom, and can be moved by a variable amount backwards, indicating a user input e.g. desired speed of lifting of the boom.

Control means (not shown) allow the operator to extend hydraulic ram 40 thereby causing the telehandler implement 36 to rotate clockwise (when viewing figure 1) about pivot 38 or to retract hydraulic ram 40 thereby causing the material handling implement 36 to rotate anticlockwise (when viewing figure 1) about pivot 38.

Control means (not shown) allow the stabilisers 50 to be moved from their raised position (as shown in figure 1) to a lowered position (not shown) where they engage the ground 8 and help to stabilise the rotating telehandler when not travelling over the ground.

The rotating telehandler has various modes of operation, three of which are described below :Transport Mode

As shown in figure 1, arrows G and H define a longitudinal direction M of the chassis 12. Similarly the front of the operator cab 18A and the back of the operator cab 18B define a longitudinal direction N of the upper structure.

As shown in figure 1, when viewed in the direction of arrow J, the longitudinal direction M of the chassis is aligned with the longitudinal direction N of the upper structure. Typically, when in transport mode, i.e. the rotating telehandler 10 is being driven from one location to another location without any load being handled, the longitudinal direction M and N will be aligned so that the front 18A of the operator cab 18 faces directly in the direction of travel G of the machine. Under these circumstances it is desirable to align the longitudinal directions N and M.

Lift and Load Mode 1:- No Slew - Vehicle moving over ground

The machine can be used to lift material e.g. from the ground by using the telescopic action of the telescopic boom, and actuators 40 and 30. Once the material has been lifted, the machine can be driven over the ground to a different position where it is desired to deposit the material, whereupon the operator can selectively operate the telescopic boom in conjunction with actuators 40 and 30 due to deposit the load. Because the vehicle is steered as it travels over the ground, is it not necessary, in this mode, to slew the upper structure relative to the lower structure, and again, typically the longitudinal direction N and M will remain aligned during such a lift and load process.

Lift and Load Mode 2:- Slew - Chassis Stationary

Alternatively, the chassis can remain stationary whilst a lift and load operation is carried out. Typically under these circumstances the stabilisers 50 will be lowered into engagement with the ground 8. Under these circumstances the operator will manoeuvre the material handling implement 36 to a position where it can pick up material by selectively controlling actuators 30, 40, the telescoping of the boom and also the slewing of the upper structure relative to the lower structure by controlling the slew motor 46. Once the material has been picked up the operator can then manoeuvre the material handling implement 36 to a position where it is desired to deposit the material, again by selectively operating actuators 40, 30, the telescoping of the boom, and the slew motor 46.

Some lift and load tasks when the chassis is stationary require the repeated lifting of material from one position and repeated depositing of material at a second position.

As will be appreciated, it is sometimes desirable to quickly align the upper structure at a particular rotatable position relative to the lower structure, for example when changing operations from a stationary lift and load task to a transport task, or when a stationary lift and load task is a repetitive task requiring the upper structure to be slewed to either a lift location or to a load location.

As shown in figure 2, the control system 48 includes a processor. The processor receives signals from the joystick 24, the second operator input device 26, and the rotational position sensor 44. The protocol shown in figure 3 may be stored in memory 54. An output signal from the control system 48 controls the actuator 46 which in turn controls rotation of the upper structure relative to the lower structure.

A user demand is inputted by moving the joystick to the right or left which provides a signal proportional to the amount of movement right or left. This proportional signal is received by the control system 48. However, the output signal from the control system is based on the control signal from joystick 24, the signal from the second operator input device 26, the signal from the rotational position sensor 44, and the protocol as shown in figure 3. A signal provided by the joystick may be an electrical signal. The signal provided by the second input device may be an electrical signal. The signal provided by the rotational positional sensor 44 may be an electrical signal. Thus, the output signal from the control system may be an electrical signal which may control electro hydraulic solenoids to supply a pressurised supply of hydraulic fluid to the hydraulic actuator 46, thereby controlling rotation of the upper structure relative to the lower structure.

The present invention provides a method whereby the operator can align the first part with the second part at an alignment positron quickly, but in a controlled manner such that the first part comes to a controlled stop at the correct alignment position, i.e. without suddenly stopping the slewing action. This reduces operator fatigue and reduces loads applied to the machine, and helps to maintain stability.

Example 1

Consider the scenario where the operator wishes to align the longitudinal direction N of the upper structure with the longitudinal direction M of the lower structure.

Firstly, the operator actuates the second operator input device 26 which may be a button, switch or the like, which indicates a desire to align the upper structure with the lower structure at an alignment position. In this case the alignment position is with the longitudinal direction N of the upper structure aligned with longitudinal direction

M of the lower structure. For purposes of explanation, this alignment position is hereafter referred to as a zero skew angle.

In this example, the upper structure is initially positioned 90 degrees anticlockwise to the zero skew angle position. In order to move the upper structure to the zero skew angle position the operator operates the joystick to rotate the upper structure clockwise relative to the lower structure. In this example, the operator moves the joystick to the fully right position, indicating a user input e.g. desire to slew the upper structure clockwise at the maximum speed. Under normal circumstances, the upper structure would continue to rotate (i.e. would rotate past the lower position clockwise) at a maximum speed. However, since the second operator input device has been operated, rather than rotating past the alignment position the upper structure will rotate as shown in figure 3 and come to a controlled halt at the alignment position.

With reference to figure 3 there is shown a protocol which defines a relationship between a maximum speed of rotation of the upper structure (when the machine is operating at the instantaneous machine parameters) and an actual speed of rotation of the upper structure.

The maximum speed of rotation of the upper structure at any particularly time depends upon the machine parameters the machine is operating at. Thus, when the machine includes a combustion engine, and that combustion engine is running at maximum speed, thereby driving a hydraulic pump at maximum speed, and slewing of the upper structure relative to the lower structure is the only demand on the hydraulic circuit, then the maximum speed of rotation may be relatively quick. Alternatively, when the engine is running relatively slowly, and there are other hydraulic services requiring hydraulic flow in addition to the slew motor (actuator 46), then the maximum speed of rotation may be less.

In the present example, starting with the upper structure skewed 90 degrees anticlockwise to the alignment position, i.e. at point R of figure 3, when the operator moves the joystick to the maximum right position, the upper structure will slew in a clockwise direction at a maximum speed towards the alignment position. However, when the upper structure reaches 20 degrees from the alignment position, i.e. position S, the speed of clockwise rotation starts to slow. By the time the upper structure has reached 14 degrees from the alignment position it will only be rotating at 90% of its maximum speed (see position T). By the time the upper structure has reached 10 degrees from the alignment position it will be rotating at 85% of its maximum speed (see position U). By the time the upper structure has reached 2 degrees from the alignment position it will be travelling at 10% of its maximum speed (see position V). Once it has reached the alignment position it will come to a stop (see position W).

Example 2

Consider the scenario where the upper structure is again positioned 90 degrees anticlockwise from the alignment position. However, under these circumstances the operator, rather than moving the joystick to the full right position, only moves the joystick 85% of the way to the full right position. Under these circumstances, the system will start at position R2 shown in figure 3 and will rotate at 85% of the maximum speed in a clockwise direction until the upper structure reaches 10 degrees from the alignment position (position U) whereupon it will progressively decrease in rotational speed. By the time the upper structure reaches 2 degrees from the alignment position the speed will have dropped to 10% of the maximum speed (point V) and the upper structure will stop rotating when it reaches the alignment position (position W).

Example 3

With the upper structure positioned 90 degrees anticlockwise from the alignment position, the operator moves the joystick 10% of its maximum travel to the right. Under these circumstances, starting at position R3 on figure 3, the upper structure will rotate relatively slowly in a clockwise direction at 10% of the maximum speed, until such time as the upper structure reaches 2 degrees of the alignment position (i.e. position V of figure 3) whereupon the rotational speed will progressively decrease and will stop when the upper structure aligns with the lower structure (position W).

As will be appreciated, if the upper structure is rotating relatively fast, for example at a maximum speed, then in order to come to a controlled halt at the alignment position, the control system 48 needs to intervene relatively early (in the above example 20 degrees from the alignment position), whereas if the upper structure is rotating relatively slowly (for example at 10% of the maximum speed) then the control system 48 only needs to intervene relatively late (for example 2 degrees from the alignment position).

An operator may choose to slew the machine quickly when it is safe to do so e.g. when there are no other operators outside the vehicle and when the area outside the vehicle is relatively clear of obstacles. Alternatively, if other operators are outside the vehicle and/or if the area outside the vehicle has several obstacles, then the operator may choose to slew relatively slowly.

As will be appreciated, if the upper structure is positioned clockwise of the alignment position and the upper structure is slewed anticlockwise to move it towards the alignment position, then the line as defined by positions S1,T1,U1,V1 and W applies.

Example 4

In the above examples, the alignment position is at zero degrees skew (i.e. when the longitudinal direction N of the upper structure is aligned with the longitudinal direction M of the lower structure). In a further example, the alignment position may not be at zero degrees skew. Furthermore, it may be desired to move the machine quickly between two alignment positions.

Thus, with reference to figure 4 there is shown a protocol defining a relationship wherein there are two alignment positions, a first alignment position at 80 degrees anticlockwise and a second alignment position at 20 degrees clockwise. The operator can choose one or more desired alignment positions by operating an appropriate operator input device. In one example, the operator may move the upper structure to a particular position and then operate an operator input device to indicate that that position is an alignment position. An operator may then move the upper structure to another position, and operate an operator input device to indicate that that second positions is also an alignment position. Once the two alignment positions have been set (in the example of figure 4, 80 degrees anticlockwise and 20 degrees clockwise), then the system will progressively slow and then stop the upper structure as it approaches either alignment position. Typically, when the upper structure has become aligned at 80 degrees anticlockwise, the operator will move the upper structure clockwise to move to the 20 degrees clockwise position (since the upper structure only has to rotate through 100 degrees). However, if the circumstances require, the operator can move anticlockwise from the 80 degree position and rotate the upper structure 260 degrees to arrive at the 20 degree alignment position. In any event, as the upper structure approaches the 20 degree alignment position it will progressively slow and then stop provided the second operator input device 26 has been operated.

Figures 3 and 4 show particular protocols used to slow slewing of the upper structure as it reaches the alignment position. Clearly different protocols could be used, in particular control system could start to slow slewing at an angle greater or less than 20 degrees. Similarly the actual speed of rotation compared to the maximum speed of rotation at any particular angle or position relative to the alignment position could be faster or slower than as shown in figure 3.

As shown in figure 3, the control system slows slew rotation based upon the maximum speed of slew and not upon the user input speed of rotation. In further embodiments the controller could control slowing of rotation based on a user input speed of rotation.

Figure 1 shows ram 30, in further embodiments there may be two or more rams carrying out the function of ram 30.

Figure 1 shows a boom with a first part which is telescopic relative to a second part.

In further embodiments there may be multiple telescopic slideable booms.

As described above, moving the joystick 24 to the right causes the upper structure to slew in a clockwise direction and moving the joystick to the left causes the upper structure to slew anticlockwise. Certain territories have certain control patterns, i.e. a certain pattern of movement of joysticks equating to movement of certain parts of the machine structure. The present invention is applicable to all control patterns.

As described above, the lift and load mode 1 does not require slewing as the vehicle 5 moves over the ground, whereas the lift and load mode 2 slewing is required but the vehicle does not move over the ground since the chassis is stationary. A further lift mode is possible where the vehicle does move over the ground and slewing occurs, and the present invention is applicable to this mode also.

Claims

1. A method of operating a load handling machine, the machine having a first part rotatably mounted relative to a second part, the first part defining a load handling arm, an actuator for rotating the first part relative to the second part, a sensor system for determining the rotational position of the first part relative to the second part, a first operator input device operable by a variable amount for indicating a user input speed of rotation of the first part relative to the second part, a second operator input device for indicating a need to align the first part relative to the second part at an alignment position, and a control system for receiving signals from the sensor system, the first operator input device and the second operator input device, the control system being operable to slow and stop the actuator, the method including the steps of

2. A method as defined in claim 1 wherein during step b) as the first part approaches the alignment position the control system controls the actuator to progressively slow the actual speed of rotation of the first part below the user input speed of rotation.

3. A method as defined in claim 1 or 2 wherein step b) starts when the first part is at an a first angle relative to the alignment position, the first angle being in the range 30 degrees to 10 degrees, alternatively 25 degrees to 10 degrees, alternatively 25 degrees to 15 degrees.

4. A method as defined in any preceding claim wherein during step b) the actual speed of rotation is 50% of a maximum speed of rotation when the first part is at a second angle relative to the alignment position, the second angle being in the range 8 degrees to 2 degrees.

5. A method as defined in any preceding claim in which during step b) the actual speed of rotation is 75% of a maximum speed of rotation when the first part is at a third angle relative to the alignment position, the third angle being in the range 15 degrees to 5 degrees.

6. A method as defined in any preceding claim wherein during step b) the actual speed of rotation is 10% of a maximum of speed of rotation when the first part is at a fourth angle relative to the alignment position, the fourth angle being in the range 4 degrees to 1 degree.

7. A method as defined in claim 1 wherein the control system includes a processor configured to control the actuator.

8. A method as defined in claim 7 wherein step b) starts at a predetermined value, the predetermined value being stored in memory accessible by the processor.

9. A method as defined in any preceding claim wherein the actuator is a hydraulic actuator.

10. A method as defined in claim 9 wherein the hydraulic actuator is a hydraulic motor.

11. A method as defined in any preceding claim wherein the first part further defines an operator cab.

12. A method as defined in any preceding claim wherein throughout step b) the 5 first operator input device is held at a position indicative of a maximum user input speed of rotation.

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GB1704977.6

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